30 Coelenterata. 



is only the main stem and some of the older branches which show any dead 

 coral. The large nematocysts of M. are oval or almost spherical and the long 

 thread has a broad belt of thorns in the middle, those of Sty. are narrower, 

 almost spindle-shaped and the belt of thorns is at the base of the thread; 

 the 3-spined nematocysts so characteristic of J/. have not been found in 

 any Stylasterid. The solid scalariform endoderm of the dactylozooids of Sty. 

 indicates a greater specialisation than the simpler hollow endoderm of the 

 dactylozooids of M. The trophodisc of the female gonophore is a marked 

 character of Sty., there are free medusae in M. Stenohelia should be merged 

 with Stylaster and Lepidopora with Errina. Distichopora has been found in 

 shallow water only, E., Cryptohelia and Conopora in deep water (204-1633 m.). 

 In Styl., which extends from shallow into deep-water (0-1633 m.), the deep-water 

 specimens are more readily arranged into specific groups and it is possible 

 that isolation in deep-sea localities has led to differentiation of species; the 

 shallow-water forms throughout the world probably represent only one true 

 species. The fistulose or tubular main stem of Sty. amphiheloides , E. labiata 

 and Co. tennis is found in many cases to contain a Nereis or Alpheus, pro- 

 bably the young colony gradually enclosed the epizoite, the fistulose character 

 of the stem is therefore to be regarded as of little value. It is still difficult 

 to separate Sty. and Allopora, but colonies of the latter are generally more 

 robust, the male ampullae more deeply seated, less prominent at the surface, 

 and the tubular spout of the testis longer and more definite than in S. There 

 are probably more gonophores (4-5) in each male ampulla in S. than in A. 

 The number of tentacles of the gastrozooids is too variable for diagnostic pur- 

 poses. The authors describe the skeleton, polyps and ampullae of Stylaster 

 11 (5 n.) and divide S. eximius into 4 fades. The method of growth seems 

 to be influenced by the production of ampulla, a large production of gonads 

 seems to retard growth in length, the thickness of the branches increases con- 

 siderably and the cyclosystems become relatively smaller. Errina 2 (1 n.), the 

 ampullae are prominent, scattered, there are several male gonophores with 

 branching spadix, in each ampulla; one female gonophore in each ampulla. 

 Distichopora 1, Cryptohelia 5 (5 n.) and n. nom. pro C. pudica Moseley, non M. E., 

 ampullae in connection with cyclosystems, several female and numerous male 

 gonophores in each ampulla, male gonophore without spadix. Conopora 2 (1 n.), 

 female ampullae unknown, ampullae occur in male as a slight swelling around 

 the cyclosystems, very numerous gonophores in each ampulla. Steganopora n. 

 1 sp., the gastrozooids and dactylozooids are very long, penetrate deeply into 

 the stem and are in close communication by means of short broad canals. 

 In consequence of close proximity of the zooids each has not a separate and 

 distinct pore, it has not a true base and therefore there are no styles. The 

 gastropores lie concealed among the long tubular dactylopores. There are 

 several gonophores in each ampulla and a spadix is present in the male gono- 

 phore. 



Marenzeller( 1 ) describes Errina gracilis n. in which there are small conical 

 dactylozooids (.07-. 12 mm. long) and also nose-shaped elevations each with a 

 small slit-like opening. The formation of these latter may be readily followed 

 on examining the tip of a branch. At the sides of a circular pore which is 

 indistinguishable from the small dactylopores the ccenenchym becomes raised 

 into two slender parallel folds which enclose a groove, the pore and groove 

 look like a semicolon. The folds then become connected by an arched ele- 

 vation near the pore, and closure proceeds until the definitive condition is 

 reached. At the ends of the branches where growth is most active almost 



